In the usual procedure of fluid transfusion or blood collection for the patient and others, a needle mounted to the distal end of a syringe, a needle mounted to the distal end of a tube connected to a container for fluid transfusion or blood collection, or an indwelling needle inserted through a hollow plastic needle and left in the patient's blood vessel and the like is used. Each of these needles has a sharp point. Therefore, they pose a risk of inadvertent pricking accidents where physicians, nurses, or disposal contractors might mistakenly prick their fingers with the needle tip. Once such an accident occurs, there is a risk of infectious diseases transmitted by the blood on the needle tip.
For this reason, needles with a protector that protects the needle tip without exposing it outside when being removed from the patient and others have recently started to become popular in order to prevent inadvertent pricking accidents from happening.
One of the examples of this needle tip protector is the one mounted to a needle comprising a protector main body with an insertion hole where the needle is inserted into and multiple elastic fingers placed so as to extend toward the needle tip, wherein the multiple elastic fingers are in the state of elastic deformation in one direction away from the needle, and the distal end of each elastic finger comes in contact with the outer surface of the needle inserted into the insertion hole of the protector main body in a slidable way (for example, see Patent Document 1 below). When such a needle provided with a protector is retracted from the patient and others, the needle moves relative to the protector while sliding over the distal end of the multiple elastic fingers. Such a movement of the needle allows each elastic finger to restore from the state of elastic deformation when the needle tip is placed in between the multiple elastic fingers. This allows the needle tip to be covered and protected by the multiple fingers.
Also, another kind of needle tip protector is known, comprising an elastic spring clip having, in an integrated manner, a supporting plate provided with an insertion hole where a needle is inserted into, and an extension plate stretching out from the supporting plate toward the needle tip and provided at the distal end with a protection part capable of covering the needle tip, wherein the extension plate is mounted to the needle while contacting the outer surface of the needle in a slidable way in the state of elastic deformation in a side direction away from the needle (for example, see Patent Documents 2 and 3 below). When this needle provided with a protector is retracted from the patient and others, the needle moves relative to the protector while sliding toward the extension plate. And, such a movement of the needle allows the extension plate to restore from the state of elastic deformation when the contact between the needle and extension plate is released. This allows the needle tip to be covered and protected with a protection part at the distal end of the extension plate.
Thus, in using a needle that can be fitted with a conventional needle tip protector, the needle tip can be protected without a special procedure for protection when being retracted from the patient and others.
However, each of these conventional needle tip protectors is mounted to a needle with its elastically deformed part contacting the outer surface of the needle. For this reason, it has been inevitable that the needle's sliding resistance against the protector is increased, thereby increasing the force needed to protect the needle tip when the needle provided with the protector is retracted from the patient and others while being moved relative to the protector. And, the larger the force to protect the needle tip, the more difficult it gets to perform the protection procedure by one hand, thereby posing a risk of making it hard to protect the needle tip right after retracting the inner needle or to surely move the needle relative to the protector to a location where the needle tip is protected.